(27,93-4,2*5.6):2,1-0,1

Assuming ":" means division and the comma is a decimal separator (27,93 = 27.93, 4,2 = 4.2, 2,1 = 2.1, 0,1 = 0.1):

• 4.2 × 5.6 = 23.52
• 27.93 − 23.52 = 4.41
• 4.41 ÷ 2.1 = 2.1
• 2.1 − 0.1 = 2.0

Answer: 2.0

If you intended 5,6 instead of 5.6 or a different decimal format, the result is still 2.0 with consistent decimals.